Radio source feedback in galaxy evolution

TL;DR

This paper introduces a galaxy evolution model that incorporates physically motivated AGN feedback via radio jets, successfully reproducing observed galaxy properties and providing insights into black hole growth and star formation history.

Contribution

It presents a novel galaxy evolution model with a detailed implementation of AGN radio feedback, linking jet activity to galaxy and black hole co-evolution.

Findings

Reproduces observed star formation histories up to high redshifts.

Explains galaxy colour bimodality through radio feedback.

Suggests a top-heavy IMF at z>2 consistent with various observations.

Abstract

We present a galaxy evolution model which incorporates a physically motivated implementation of AGN feedback. Intermittent jets inflate cocoons of radio plasma which then expand supersonically, shock heating the ambient gas. The model reproduces observed star formation histories to the highest redshifts for which reliable data exists, as well as the observed galaxy colour bimodality. Intermittent radio source feedback also naturally provides a way of keeping the black hole and spheroid growth in step. We find possible evidence for a top-heavy Initial Mass Function (IMF) for $z>2$, consistent with observations of element abundances, and sub-mm and Lyman break galaxy counts.